Abstract: An object of the present invention is to provide a thermostable DNA polymerase with enhanced amplification efficiency and/or improved fidelity in polymerase chain reaction (PCR), and provide a process for production thereof. More specifically, the present invention provides thermostable DNA polymerase wherein in the DX1EX2X3X4H sequence (D: aspartic acid, E: glutamic acid, H: histidine, X1, X2, X3 and X4: any amino acid) consisting of DX1E sequence within the EXO I region and a four amino acid length peptide adjacent to said glutamic acid(E) of thermostable DNA polymerase having 3?-5? exonuclease activity, histidine(H) has been replaced by another amino acid.

Abstract: The invention provides methods, kits, and compositions for enhancing synthesis of DNA involving a carboxylate ion-supplying substance that is effective in promoting DNA synthesis in enzymatic DNA synthesis reactions. The invention further provides a thermostable DNA polymerase-related factor derived from Thermococcus species, which has an activity to promote the DNA synthesis activity of DNA polymerase or which binds to DNA polymerase.

Abstract: A composition for enhancing synthesis of DNA comprising an anion-supplying substance that is effective in promoting DNA synthesis in enzymatic DNA synthesis reactions, in particular a salt of a dicarboxylic acid. Further enhanced DNA synthesis promoting effects can be achieved by using, together with the anion-supplying substance, at least one compound selected from the group consisting of dimethylsulfoxide and compounds represented by the following formula (1): R2—CH2—NR1xHy??(1) wherein R1 is an alkyl group having 1 to 3 carbon atoms, R2 is a substituent selected from the group consisting of the following (a) and (b): (a) oxygen and (b) radicals represented by the formula wherein R4 is methyl, hydrogen or forms a pyrrolidine ring when combined with R1, R5 is —CO2H or —SO3H, and n is an integer from 0 to 2, x is an integer from 1 to 3 and y is an integer from 0 to 2, provided that x plus y equals 3.

Abstract: An object of the present invention is to provide a thermostable DNA polymerase with enhanced amplification efficiency and/or improved fidelity in polymerase chain reaction (PCR), and provide a process for production thereof. More specifically, the present invention provides thermostable DNA polymerase wherein in the DX1EX2X3X4H sequence (D: aspartic acid, E: glutamic acid, H: histidine, X1, X2, X3 and X4: any amino acid) consisting of DX1E sequence within the EXO I region and a four amino acid length peptide adjacent to said glutamic acid(E) of thermostable DNA polymerase having 3′-5′ exonuclease activity, histidine(H) has been replaced by another amino acid.

Abstract: A modified thermostable DNA polymerase having 5% or less of the 3'-5' exonuclease activity of the enzyme before modification and a DNA polymerase composition for amplifying nucleic acid, which comprises the modified thermostable DNA polymerase having 0 to 5% of the 3'-5' exonuclease activity of the enzyme before modification and an unmodified thermostable DNA polymerase having 3'-5' exonuclease activity or a modified thermostable DNA polymerase having 100 to 6% of the 3'-5' exonuclease activity of a thermostable DNA polymerase before modification; a method for amplifying nucleic acid by use of said modified thermostable polymerase or said DNA polymerase composition; and a reagent therefor.